Cup holder adapter



FIG. 1 is a front elevational photographic view of a cup holder adapter, showing my new design;

FIG. 2 is a rear elevational photographic view thereof;

FIG. 3 is a left side elevational photographic view thereof;

FIG. 4 is a right side elevational photographic view thereof;

FIG. 5 is a top plan photographic view thereof;

FIG. 6 is a bottom plan photographic view thereof; and,

FIG. 7 is a perspective photographic view thereof. 

CLAIM I claim the ornamental design for a cup holder adapter, as shown and described. 